IPA_Emulation: Call f_IPL4_setGetMsgLen for both client and server

So far, only the IPA client was instructing the IPL4asp to use
the message-desegmentation function.  The server didn't use it, leading
to inconsistent behaviour.
diff --git a/library/IPA_Emulation.ttcn b/library/IPA_Emulation.ttcn
index 5450031..ddedb39 100644
--- a/library/IPA_Emulation.ttcn
+++ b/library/IPA_Emulation.ttcn
@@ -157,10 +157,6 @@
 						local_host, local_port, 0, { tcp:={} });
 	g_ipa_conn_id := res.connId;
 	g_ccm_pars := ccm_pars;
-	/* Set function for dissecting the binary */
-	var f_IPL4_getMsgLen vl_f := refers(f_IPL4_fixedMsgLen);
-	IPA_CodecPort_CtrlFunct.f_IPL4_setGetMsgLen(IPA_PORT, g_ipa_conn_id, vl_f, {0, 2, 3, 1, 0});
-
 	g_is_bsc_mgw := true;
 }
 
@@ -372,6 +368,10 @@
 	var octetstring payload;
 	var ASP_RSL_Unitdata rsl;
 
+	/* Set function for dissecting the binary */
+	var f_IPL4_getMsgLen vl_f := refers(f_IPL4_fixedMsgLen);
+	IPA_CodecPort_CtrlFunct.f_IPL4_setGetMsgLen(IPA_PORT, g_ipa_conn_id, vl_f, {0, 2, 3, 1, 0});
+
 	while (true) {
 		alt {
 		/* Received IPA -> up into SCCP stack */